Copy render settings between scenes using Python
There is this bundled addon for this:



If you specifically need the python code, you can do it like this:

import bpy
settings = ["resolution_x", "resolution_y", "resolution_percentage"]
dict = {sett: getattr(bpy.context.scene.render, sett) for sett in settings}
for scene in bpy.data.scenes:
    for sett, val in dict.items():
        setattr(scene.render, sett, val)